New data from app performance experts Crittercism suggests the Apple Watch is driving iOS upgrades, with a sudden boost in Watch-compatible iOS upgrades seen since April. The data also shows that Apple Watch has extremely low app crash rates.

When the Apple Watch was first made available for pre-order on April 10, just 51% of iOS devices were running Watch-compatible firmware (iOS 8.2 and above). By the time the device launched on April 24, that percentage had risen to 61%.

As things currently stand, 70% of iOS devices are now running iOS 8.2 and above, Crittercism reports.

It’s thought one of the reasons for this increase is that iPhone owners are updating their devices to use the Apple Watch. Another reason is that Apple fans are buying new iPhones with the latest software pre-installed alongside an Apple Watch.

On April 10, only 35% of iPhones in use were compatible with Apple Watch (that’s the iPhone 5, iPhone 5c, iPhone 5s, iPhone 6, and iPhone 6 Plus). But by the end of May, that figure had reportedly risen to 50%.

Crittercism’s data also shows that Apple Watch has incredibly impressive app crash rates. When it first launched, the app crash rate was just 0.00833%, while now it’s around 0.01233%. That’s much lower than the “desired crash rate” of 1%.